Latch needle for knitting machines or the like



May 1, 1962 w. WIEDERHUT ETAL 3,031,867

LATCH NEEDLE FOR KNITTING MACHINES OR THE LIKE Filed June 22, 1959INVENTORS WOLFGANG W/EDERHUT MAX BAA/HAMMER W {t -Mum.

ATTORNEYS United States Patent Ofiiice 3,031,867 Patented May 1, 19623,031,867 LATCH NEEDLE FOR KNITTING MACHINES OR THE LIKE WolfgangWiederhut and Max Danhammer, Ebingen, Germany, assignors to Theodor Groz& Sohne & Ernst Beckert Nadelfabrik Commandit-Gesellschaft, Ebingen,Wurttemberg, Germany, a corporation of Ger- Filed June 22, 1959, Ser.No. 821,774 Claims priority, application Germany July 28, 1958 2 Claims.(Cl. 66-121) The present invention concerns a latch needle for knittingmachines or the like.

According to the present invention a latch needle for knitting machinesor the like, comprises a latch adapted to pivot in a slot in the needlestem, the free end of the latch being adapted to rest, when the latch isin its extreme rear position, in a recess formed in the needle stemwhich serves as an abutment surface and is formed by.- an impression inthe needle stem.

The invention will be described further, by way of example, withreference to the accompanying drawings, in which:

FIG. 1 is a side elevation, partly in section, of a latch needle ofconventional design;

FIG. 2 is a corresponding plan the latch being omitted;

FIG. 3 is a cross-section taken on the line I-I of FIG. 1;

FIG. 4 is a side elevation, partly in section of a needle constructed inaccordance with the invention;

FIG. 5 is a corresponding plan, the latch being omitted;

FIG. 6 is a section on the line II--II of FIG. 4;

FIG. 7 is a side elevation, partly in section, of an alternativeembodiment of needle constructed in accordance with the invention;

FIG. 8 is a corresponding plan, the latch being removed; and

FIG. 9 is a section on the line III--III of FIG. 7.

The latch lever shown in FIGS. 1-3 comprises a stem 1, a hook 2 beingformed at one or both ends thereof. The needle stem 1 has a slot 3 inwhich a latch 4 is rotatably journaled on a spindle 5. The stem of thelatch 4 terminates in a blade-like enlarged latch head 6 which in oneterminal position of its pivotal movement executed during the knittingoperation (shown in chain dotted lines in FIG. 1) rests on the hook 2,whereas, in the other terminal position (shown in full lines and termedrear position of latch) the back of the blade 6 abuts a lenslikeenlarged recess 7 of the slot 3 in the needle stem 1.

This recess 7 is usually formed by milling. The form of the recess 7resulting from the shape of the milling tool used, causes the back ofthe blade to rest on a punctiform surface of the needle stem which islocated at an acute angle to the plane of movement of the latch and alsodetermines the dimension a between the lower edge of a needle stem 1 andthe upper edge of the latch blade.

This dimension a must be kept within very strict tolerances in order toachieve regular stitch formations in the knitting machine and should bekept as small as possible, in order to allow slight enlargement of thestitch as it slides over the opened latch.

In the embodiment shown in FIGS. 4 to 6, the stem of the needle has beensubjected to pressure by a press die on both sides of the slot 3 at apoint 9 so that spoonshaped projecting shoulders 9, extending into theslot 3, are produced on both side walls of the slot 3. The back of theblade of the latch 4, in its extreme rear position, abuts flush againstthe projections 9 which results in less Wear than a purely punctiformabutting surface and is perpendicular to the plane of movement of thelatch, thus rendering it possible to maintain the tolerances and whichcan be provided with a large area by adapting the shape of the press dieemployed to the form of the back of the blade, also making it possibleto keep the depth of counter-sinking equal to the dimension a by meansof the depth of the pressing movement. Old or new latch needles can thusbe used in the knitting machine.

The impression formed may not only extend into the bearing region of thestraight back of the latch stem, but similarly also over the full stembehind the end of the needle slot, if the material displaced during theimpressing can still be pushed back into the slot; the latter case isshown in FIGS. 7 to 9. In these FIGURES, an abutment surface isimpressed to support the back of the needle and extends in a region 10over the solid stem portion, the material of which is pushed back intothe slot 3, the surface extending in a region 11 in the original slot 3and on both sides thereof.

What we claim is:

I. In a latch needle for knitting machines or the like having a stemwith a slot therein, a latch being pivotally arranged in the slot insaid stem, and a recess in said stem, said recess being an impressionadapted to serve as a support for said latch and engaging the latch withsubstantially surface portions thereof when said latch is in the extremerearward position, said impression being formed of projections of thewalls of the slot by displaced stem material in the slot.

2. In a latch needle for knitting machines or the like having a stemwith a slot therein, according to claim 1, wherein said impressionextends along the entire stem portion beyond the end of the slot.

References Cited in the file of this patent UNITED STATES PATENTS956,318 Egly Apr. 26, 1910 1,874,457 Corey Aug. 30, 1932 1,997,530 MillsApr. 9, 1935 2,015,609 Swinglehurst Sept. 24, 1935 2,252,302 Morith Aug.12, 1941 2,282,824 Primm May 12, 1942 2,817,222 Noe Dec. 24, 1957

